In order to suppress occurrence of car accidents during night to improve safety of car society, it is proposed to always use a headlight of a car during running as a high-beam headlight. Accordingly, in order to avoid glare on a car running ahead and an oncoming car while basically brightly illuminating eyesight of a driver during the running, an illumination apparatus on which a technique that is called Adaptive Driving Beam (ADB) partially turning off the headlight in accordance with surrounding circumstances has started to be practically used.
For example, a Patent Document 1 discloses a headlight apparatus and a luminance control method capable of adjust the luminance by determining whether it is necessary to dim the light of the own car. Specifically, the headlight apparatus has a state detecting means configured to detect a headlight state in which the headlight is being tuned on and a dimming controlling means configured to decrease the luminance of the headlight to a predetermined value larger than zero in accordance with the headlight turning-on state.
A Patent Document 2 discloses a light-distribution adjusting method and an illumination apparatus that prevent excessiveness and lack of luminance of each of illuminated objects close to and far from the illumination apparatus by acquiring each luminance of a plurality of partial regions corresponding to each of a plurality of light-distributing change elements forming a light-distribution changing unit from an image in an illuminated range under illumination light and by controlling optical parameters of each of the plurality of light-distributing change elements on the basis of each luminance, and discloses an imaging apparatus having an illumination apparatus that prevents excessiveness and lack of light exposure onto each imaged object close to and far from the illumination apparatus.